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Kim, Y.-J.

Publications and source records attributed to Kim, Y.-J..

At least 19 recordsLinked to original sources

Tabular Foundation Models Are Competitive Cellular Perturbation Predictors Across Biological Scales

Predicting how cells respond to genetic and chemical perturbations is a central challenge in drug discovery and functional genomics. A growing ecosystem of specialized single-cell foundation models has been developed to address this problem, yet their practical advantage over domain-agnostic approaches remains unclear. Here we evaluate the power of Tabular Foundation Models such as TabICL and TabPFN, general-purpose pre-trained regression models, against domain-specific architectures including PRESAGE, scGPT, scLAMBDA, STACK and Prophet across four complementary evaluation settings: cell-level in-context cross-cell-type prediction, pseudobulk perturbation prediction on five Perturb-seq datasets of cell-lines, a genome-wide CRISPR screen in primary human CD4+ T cells, and embryo-level cell-type composition prediction in a zebrafish developmental perturbation atlas. In the cell-level cross-cell type perturbation prediction, Tabular Foundation Models perform on par or better than specialized models. On pseudobulk perturbation prediction, Tabular Foundation Models consistently out-perform specialized baselines across multiple evaluation metrics and datasets. On whole-embryo cell-type composition prediction, Tabular Foundation Models are competitive with specialized baselines. These results demonstrate that general-purpose tabular in-context learning provides a strong and scalable alternative to bespoke biological architectures for perturbation response modeling across cell systems and scales.

bioinformatics↗

RNAquarium: an archive-scale atlas of zebrafish gene expression coupled with pan-taxonomic profiling reveals diverse viral drivers of transcriptomic states

Zebrafish RNA-seq studies span diverse developmental, physiological, and disease contexts, yet most analyses remain confined to individual experiments and disregard the non-zebrafish component of the data. We present RNAquarium, a scalable framework for joint transcriptomic and metatranscriptomic analysis of RNA-seq data and apply it to all publicly available zebrafish RNA-seq datasets in the Sequence Read Archive. This resource captures transcriptomic structure across development and tissues, reveals diverse microbial and viral associations, and identifies previously undescribed zebrafish viruses including a close relative of human influenza B virus linked to distinct host transcriptional states. We further demonstrate that archive-scale transcriptomes can support foundation-model training and prediction of infection-associated transcriptomic signatures. RNAquarium provides an open framework and interactive portal for exploring the breadth of zebrafish gene expression patterns and associated taxa profiled across a large re-search community and establishes a generalizable strategy for integrating transcriptomic and metatranscriptomic analyses across the diversity of life represented in public sequencing archives.

genomics↗

The fungicide mancozeb induces astrocyte atrophy and disrupts Calcium signaling via inhibition of Orai1/STIM1-mediated SOCE

Mancozeb, a widely used fungicide composed of manganese ethylene-bis-dithiocarbamate with zinc salts, has raised concerns due to its potential neurotoxic effects. In this study, we investigated how chronic oral administration of mancozeb affects astrocyte function and neurobehavior in mice, focusing on store-operated Ca{superscript 2} entry (SOCE), mediated by Orai1 and STIM1. Mancozeb treatment at 0.5 {micro}g/kg/day for 4 weeks reduced glial fibrillary acidic protein (GFAP) expression in the hippocampus and corpus callosum of mice, indicating astrocyte atrophy. Further, administration at the human acceptable daily intake (30 {micro}g/kg/day) for 1 week induced hippocampal astrocyte atrophy and hyperlocomotor activity in open field tests. In vitro experiments revealed that mancozeb specifically inhibited SOCE in astrocytes by targeting the Orai1/STIM1 complex, as its inhibitory effect was abolished by short hairpin RNA (shRNA)-mediated knockdown of Orai1 or STIM1, but not by knockdown of TRPA1 or scramble shRNA. This demonstrates that mancozeb-mediated SOCE inhibition critically depends on the presence of Orai1 and STIM1, highlighting the molecular specificity of its action. Furthermore, mancozeb diminished endoplasmic reticulum (ER) Ca{superscript 2} stores and P2Y1 receptor agonist-induced Ca{superscript 2} transients. Electrophysiological analyses revealed that mancozeb selectively decreased the inhibitory postsynaptic current frequency without affecting excitatory currents, suggesting reduced astrocyte-mediated GABA release. Collectively, these findings demonstrate that mancozeb disrupts astrocytic Ca{superscript 2} homeostasis through Orai1/STIM1-dependent SOCE inhibition, leading to astrocyte atrophy and altered inhibitory neurotransmission, which may underlie the observed behavioral changes. These results highlight the potential neurotoxic risk posed by mancozeb via the impairment of astrocyte function and intracellular Ca{superscript 2} regulation. Importantly, these neurotoxic effects occurred at concentrations below current regulatory safety limits (ADI), indicating that mancozeb-induced disruption of astrocytic Ca{superscript 2} signaling provides a mechanistic basis for re-evaluating established human safety exposure standards. Environmental ImplicationsOur findings highlight that the widespread use of mancozeb has a significant impact on brain health. Mancozeb was shown to induce astrocyte atrophy even at low concentrations, amounting to six times the human acceptable daily intake. Mancozeb causes impairment of GABAergic synaptic transmission of neurons by disrupting the Ca{superscript 2} homeostasis via inhibition of Orai1 and STIM1 of astrocytes. These findings indicate that current regulatory standards significantly underestimate the risks of long-term mancozeb exposure to brain health. Therefore, this study underscores the risks of astrocyte-mediated neurotoxicity resulting from pesticide residue ingestion and emphasizes the need to rigorously re-evaluate current exposure limits from the perspective of brain health.

pharmacology and toxicology↗

Coordinated Tuning of Ionizable Lipids and Formulation Redirects mRNA Vaccines Toward Lymphoid-Specific CD4+ T Cell Immunity

The global success of mRNA vaccines has underscored the pivotal role of lipid nanoparticles (LNPs), yet how subtle chemical variations in ionizable lipids and their formulation parameters orchestrate complex immune landscapes remains largely elusive. Here, we report a novel ionizable lipid, N4Z, and demonstrate that its distinct chemical signature selectively intensifies early innate immune programs compared to its structural analogue, N4Y. Single-cell transcriptomic profiling at the injection site reveals that N4Z-based LNPs uniquely prime inflammatory and type I interferon-related transcriptional programs, accompanied by a rapid influx of B and CD4+ T cells. Beyond lipid chemistry, we show that formulation-level tuning, that is independent of the ionizable lipid structure, can reshape the systemic biodistribution from hepatic dominance toward lymphoid tissues. This optimization substantially enhances macrophage-associated antigen expression, which in turn amplifies polyfunctional CD4+ T cell responses, T follicular helper cell differentiation, and germinal center reactions. Our findings establish that the coordinated interplay between lipid engineering and formulation design provides a programmable platform for precision mRNA vaccination, achieving superior protective efficacy and neutralizing activity over clinically validated benchmarks.

bioengineering↗

MechanoMR microparticle (M3) sensors reveal dynamic stress loading as a driver of epithelial-mesenchymal transition

The dynamic mechanical response of tissues underlies their physiological function, yet direct, quantitative measurement of tissue stress in vivo has remained a major challenge. Here, we introduce the mechanoMR microparticle (M3, "M-cube") sensor, a hybrid soft-matter/nanoparticle probe that integrates directly into tissue mechanical networks while transducing local stress into quantitative magnetic resonance (MR) readouts with single-particle resolution. We demonstrate the utility of this platform across diverse model systems, including tumor spheroids, Xenopus embryos, and mouse xenografts, where the M3 sensor enables noninvasive, spatiotemporally resolved mapping of tissue stress dynamics during cancer development. Using this approach, we reveal that epithelial-mesenchymal transition (EMT) is accompanied by distinctive stress-remodeling patterns observable in vivo. Strikingly, we find that abrupt stress increases, rather than cumulative or peak stress magnitude, are the key determinants of EMT induction in cancer cells within the tumor microenvironment. Transcriptomic profiling under controlled stress-loading dynamics shows that sustained yet gradual stress escalation activates cytoprotective antioxidation pathways (e.g., FOXO/AMPK) that reinforce epithelial stability, whereas acute stress surges overwhelm these defense mechanisms, predisposing cells toward mesenchymal reprogramming. These findings establish the M3 sensor as a broadly applicable technology for linking dynamic mechanical cues to cell-state transitions in development, homeostasis, and disease.

bioengineering↗

Matrix-rigidity cooperates with biochemical cues in M2 macrophage activation through increased nuclear deformation and chromatin accessibility

Macrophages encounter a myriad of biochemical and mechanical stimuli across various tissues and pathological contexts. Notably, matrix rigidity has emerged as a pivotal regulator of macrophage activation through mechanotransduction. However, the precise mechanisms underlying the interplay between mechanical and biochemical cues within the nuclear milieu remain elusive. Here we elucidate how the increased matrix rigidity drives macrophages to amplify alternatively-activated (M2 phenotype) signalings cooperatively with biochemical cues (e.g., IL4/13) through altered nuclear mechanics. Notably, we found that reconstructed podosome-like F-actins and contractility induced nucleus deformation, opening nuclear pores, which facilitates nuclear translocation of the key transcription factor STAT6. Furthermore, the altered nuclear mechanics increased chromatin accessibility induced by H3K9 methylation, particularly of M2-associated gene promoters. These cooperative events of the mechano-chemical signaling at the cytoskeletal-to-nuclear domains facilitated M2 transcriptional activation and cellular functions. We further evidenced the rigidity-primed M2 macrophages were immunosuppressive and accumulated in stiffened tumor tissues. This study proposes a mechanism by which matrix mechanics crosstalks with biochemical signals to potentiate macrophage activation through nuclear mechanosensing and chromatin modifications, offering insights into macrophage mechanobiology and its therapeutic modulations.

bioengineering↗

Sequential genetic, epigenetic alterations in human pluripotent stem cells for recurrent abnormality

Human embryonic stem cells (hESCs) are naturally equipped to maintain genome integrity to minimize genetic mutations during early embryo development. However, genetic aberration risks and subsequent cellular changes in hESCs during in vitro culture pose a significant threat to stem cell therapy. While a few studies have reported specific somatic mutations and copy number variations (CNVs), the molecular mechanisms underlying culture-adapted phenotype acquisitions of hESCs are largely unknown. Therefore, we conducted comprehensive genomic, single-cell transcriptomic, and single-cell ATAC-seq analyses of an isogenic hESC model displaying definitive culture-adapted phenotypes. Notably, hPSCs with a copy number gain of 20q11.21 during early passage did not present culture-adapted phenotypes nor BCL2L1 induction. Single-cell RNAseq and ATACseq analyses revealed active transcriptional regulation at 20q11.21 loci at late-passaged hESCs with the induced BCL2L1 and TPX2 to trigger culture-adapted phenotypes was associated with epigenetic changes facilitating TEA domain (TEAD) binding. These results suggest that copy number 20q11.21 gain and additional epigenetic changes are necessary for expressing culture-adapted phenotypes by activating gene transcription at this specific locus.

cell biology↗

Male cuticular pheromones stimulate removal of the mating plug and promote re-mating through pC1 neurons in Drosophila females

In birds and insects, the female uptakes sperm for a specific duration post-copulation known as the ejaculate holding period (EHP) before expelling unused sperm and the mating plug through sperm ejection. In this study, we found that Drosophila melanogaster females shortens the EHP when incubated with males or mated females shortly after the first mating. This phenomenon, which we termed male-induced EHP shortening (MIES), requires Or47b+ olfactory and ppk23+ gustatory neurons, activated by 2-methyltetracosane and 7-tricosene, respectively. These odorants raise cAMP levels in pC1 neurons, responsible for processing male courtship cues and regulating female mating receptivity. Elevated cAMP levels in pC1 neurons reduce EHP and reinstate their responsiveness to male courtship cues, promoting re-mating with faster sperm ejection. This study established MIES as a genetically tractable model of sexual plasticity with a conserved neural mechanism. Significance StatementSexual plasticity, the adaptation of reproductive behavior to social changes, was explored in the fruit fly, a genetically tractable model insect. Our findings revealed that inseminated females, encountering another courting male post-mating, shorten the ejaculate holding period (EHP). Specific olfactory and gustatory pathways regulating this phenomenon were identified, converging on the pC1 neurons in the brain-a conserved neural circuit that regulates female mating activity. Odors associated with EHP shortening increased the second messenger cAMP. The transient elevation of cAMP heightened the excitability of pC1 neurons, facilitating the prompt removal of the male ejaculate and subsequent re-mating . This study established a behavioral model of sexual plasticity and provided a framework for understanding the neural circuit processes involved.

neuroscience↗

Single-nucleus RNA sequencing provides insights into the GL261-GSC syngeneic mouse model of glioblastoma

Glioblastoma (GBM) is an aggressive tumor with very bad prognosis. The urgent need to find new effective therapies is challenged by the unique characteristics of GBM, including high intra and intertumoral heterogeneity. Using single-nucleus transcriptomics (snRNA-seq), we characterized the panorama of a preclinical immunocompetent murine model based in the implantation of mouse glioblastoma stem cells (GL261-GSCs) into the brain parenchyma. Additionally, we performed Visium spatial transcriptomics in the in vivo model to confirm the location of annotated cells. To understand the technical bias of this approach, we performed two scRNA-seq methods in GBM cells. We thoroughly characterized the tumor microenvironment (TME) at early and late stages of tumor development and upon treatment with temozolomide (TMZ), the standard of care for patients with GBM, and with Tat-Cx43266-283, a promising experimental treatment. We identified prominent GBM targets that can be addressed using this preclinical model, such as Grik2, Nlgn3, Gap43 or Kcnn4, which are involved in electrical and synaptic integration of GBM cells into neural circuits, as well as the expression of Nt5e, Cd274 or Irf8, which indicates the development of immune evasive properties in these GBM cells. In agreement, snRNA-seq unveiled high expression of several immunosuppressive-associated molecules in immune cells, such as Csf1r, Arg1, Mrc1 and Tgfb1, suggesting the development of an immunosuppressive microenvironment. We also show the landscape of cytokines, cytokine receptors, checkpoint ligands and receptors in tumor and TME cells, which are crucial data for a rational design of immunotherapy studies. Thus, Mrc1, PD-L1, TIM-3 or B7-H3 are among the immunotherapy targets that can be addressed in this model. Finally, the comparison of the preclinical GL261-GSC GBM model with human GBM subtypes unveiled important similarities with the recently identified TMEmed human GBM, indicating that preclinical data obtained in GL261-GSC GBM model might be applied to TMEmed human GBM, improving patient stratification in clinical trials. In conclusion, this work provides crucial information for future preclinical studies in GBM improving their clinical application.

neuroscience↗

Neural stem cells protect the integrity of blood-brain barrier via the p38, JNK and ERK1/2 pathways following intracerebral hemorrhage in rats

Neural stem cells (NSCs) have displayed great potential in ameliorating brain damage following intracerebral hemorrhage (ICH) via proliferation, differentiation, and immunomodulation. However, it remains unclear whether NSCs can improve microvascular function, e.g., blood-brain barrier (BBB) integrity, after ICH. In this study, we investigate the potential therapeutic benefit of NSCs on BBB integrity as well as the underlying mechanism. Adult male Sprague-Dawley rats were randomly divided into sham, ICH+PBS, and ICH+NSCs groups for comparisons. ICH was induced by intrastriatal injection of bacterial collagenase. An aliquot of NSCs or PBS was injected via the tail vein 2 h after ICH induction. The following multiparametric measurements were compared: brain edema, hematoma volume, behavior, BBB permeability, and mitogen-activated protein kinase (MAPK) signaling pathway activity. We found that NSCs treatment attenuates BBB permeability, reduces brain edema, and promotes brain function recovery after ICH by inhibiting ERK1/2, p38, and JNK signaling pathway activation. These findings provide novel insight for future therapies aiming to prevent BBB dysfunction and improve functional recovery in ICH patients.

neuroscience↗

Th17 cells target the metabolic miR-142-5p-SDHC/SDHD axis promoting invasiveness and progression of cervical cancers

During cervical carcinogenesis, T-helper (Th)-17 cells accumulate in the peripheral blood and tumor tissues of cancer patients. We previously demonstrated that Th17 cells are associated with therapy resistance as well as cervical cancer metastases and relapse, however, the underlying Th17-driven mechanisms supporting cervical cancer progression are not fully understood as yet. In this study, we found that Th17 cells promote migration and invasion of cervical cancer cells in 2D cultures and 3D spheroids. We demonstrated that Th17 cells induced the expression of miR-142-5p in cervical cancer cells supporting their migration and invasiveness. As the responsible mechanism, we identified the subunits C and D of the succinate dehydrogenase (SDH) complex as new targets of miR-142-5p and provided evidence that Th17 cells reduced the expression of SDHC and SDHD that was dependent on miR-142-5p. Functional downstream analysis with inhibitors of miR-142-5p and siRNA knock down of SDHC and SDHD revealed that Th17-induced miR-142-5p-mediated reduced expression of SDHC and SDHD was responsible for enhanced migration and invasion of cervical cancer cells. Consistently, cervical cancer patients exhibited high levels of succinate in their serum associated with lymph node metastases and diminished expression of SDHD in patients' biopsies significantly correlated with increased numbers of Th17 cells, advanced tumor stage and lymph node metastases. Correspondingly, a combination of weak or negative SDHD expression and a ratio of Th17/CD4+ T cells > 43.90 % in situ was associated with reduced recurrence free survival. In summary, we unraveled a novel molecular mechanism by which Th17 cells promote cervical cancer progression and suggest evaluation of Th17 cells as a potential target for immunotherapy in cervical cancer.

cancer biology↗

Synthetic lipid rafts formed by cholesterol nano-patch induce T cell activation

Lipid rafts cluster at the immunological synapse during activation and serve as signaling hubs in T cells. While cholesterol plays a crucial role in lipid raft formation, the impact of their spatial configuration remains less understood. Here, we introduce programmable DNA origami, cholesterol nano-patch, for nanoscale spatial control of cholesterols on live T cell membranes, enabling us to elucidate their roles in lipid raft formation, receptor activation, and intracellular signaling. We demonstrate that CNPs with high-density cholesterol arrangements efficiently bind to the T cell plasma membrane and form a large and polarized coalescence, leading to the stabilization of ordered lipid membrane domains by increasing the local concentration of cholesterols. These synthetic lipid rafts colocalize with flotillin-1, a raft-associated protein, and promote the membrane reorganization and physical segregation of key signaling molecules, such as T cell receptors, Lck and LAT kinases, and CD45. Consequently, this leads to early T cell activation in the absence of antigenic stimulation. Our DNA origami approach demonstrates the direct role of cholesterol in lipid raft formation, leading to membrane phase separation and protein reorganization, which are sufficient to induce early T cell activation.

bioengineering↗

Dopamine-Modified Hyaluronic Acid (DA-HA) As A Novel Dopamine-Mimetics With Minimal Autoxidation And Cytotoxicity

Dopamine-modified hyaluronic acid (DA-HA) has been initially developed as an efficient coating and adhesion material for industrial uses. However, the biological activity and safety of DA-HA in the brain have not been explored yet. Here, we report a series of evidence that DA-HA exhibits similar functionality as dopamine (DA), but with much lower toxicity arising from autoxidation. DA-HA shows very little autoxidation even after 48-hour incubation. This is profoundly different from DA and its derivatives including L-DOPA, which all induce severe neuronal death after pre-autoxidation, indicating that autoxidation is the cause of neuronal death. Furthermore, in vivo injection of DA-HA induces significantly lower toxicity compared to 6-OHDA, a well-known oxidized and toxic form of DA, and alleviates the apomorphine-induced rotational behavior in the 6-OHDA animal model of Parkinsons disease. Our study proposes that DA-HA with DA-like functionalities and minimal toxicity can be an effective therapeutic substitute for L-DOPA in Parkinsons disease.

neuroscience↗

Discovery and pre-clinical evaluation of antibodies to the NKG2A inhibitory receptor

NK and CD8+ T cells are important cells for cytolysis of cancer cells. The tumor microenvironment can upregulate surface expression on these cells of NKG2A, an inhibitory receptor that can dampen immune responses to cancer leading to immune evasion. To block NKG2A-mediated inhibition, we discovered and characterized two fully human antibodies using phage and yeast display that bind to NKG2A. These antibodies are highly specific for human CD94/NKG2A heterodimer complex, displaying no binding to the activating NKG2C receptor. A mutagenesis study revealed that the serine residue at 170 position (S170) of NKG2A is critical for the selectivity of anti-NKG2A antibodies. In vitro cytotoxic assays showed that NKG2A antibody inhibitors activated primary NK cells and promoted ADCC function of specific antibodies that bind to antigens expressed on cancer cells. Summary headingFully human antibodies to the NKG2A inhibitory receptor

immunology↗

Inhibitors of anti-apoptotic Bcl-2 family proteins exhibit potent and broad-spectrum anti-mammarenavirus activity via cell cycle arrest at G0/G1 phase

Targeting host factors is a promising strategy to develop broad-spectrum antiviral drugs. Drugs targeting anti-apoptotic Bcl-2 family proteins that were originally developed as tumor suppressors have been reported to inhibit multiplication of different types of viruses. However, the mechanisms whereby Bcl-2 inhibitors exert their antiviral activity remain poorly understood. In this study, we have investigated the mechanisms by which obatoclax (OLX) and ABT-737 Bcl-2 inhibitors exhibited a potent antiviral activity against the mammarenavirus lymphocytic choriomeningitis virus (LCMV). OLX and ABT-737 potent anti-LCMV activity was not associated with their pro-apoptotic properties, but rather their ability of inducing cell arrest at G0/G1 phase. OLX and ABT-737 mediated inhibition of Bcl-2 correlated with reduced expression levels of thymidine kinase 1 (TK1), cyclin A2 (CCNA2), and cyclin B1 (CCNB1) cell cycle regulators. In addition, siRNA-mediated knock down of TK1, CCNA2, and CCNB1 resulted in reduced levels of LCMV multiplication. The antiviral activity exerted by Bcl-2 inhibitors correlated with reduced levels of viral RNA synthesis at early times of infection. Importantly, ABT-737 exhibited moderate efficacy in a mouse model of LCMV infection, and Bcl-2 inhibitors displayed broad-spectrum antiviral activities against different mammarenaviruses and SARS-CoV-2. Our results suggest that Bcl-2 inhibitors, actively being explored as anti-cancer therapeutics, might be repositioned as broad-spectrum antivirals. IMPORTANCEAnti-apoptotic Bcl-2 inhibitors have been shown to exert potent antiviral activities against various types of viruses via mechanisms that are currently poorly understood. This study has revealed that Bcl-2 inhibitors mediated cell cycle arrest at the G0/G1 phase, rather than their pro-apoptotic activity, plays a critical role in blocking mammarenavirus multiplication in cultured cells. In addition, we show that Bcl-2 inhibitor ABT-737 exhibited moderate anti-mammarenavirus activity in vivo, and that Bcl-2 inhibitors displayed broad-spectrum antiviral activities against different mammarenaviruses and SARS-CoV-2. Our results suggest that Bcl-2 inhibitors, actively being explored as anti-cancer therapeutics, might be repositioned as broad-spectrum antivirals.

microbiology↗

TPX2 Amplification-Driven Aberrant Mitosis in Long-Term Cultured Human Embryonic Stem Cells

Although human embryonic stem cells (hESCs) are equipped with highly effective machinery for the maintenance of genome integrity, the frequency of genetic aberrations during long-term in vitro hESC culture has been a serious issue that raises concerns over their safety in future clinical applications. By passaging hESCs over a broad range of timepoints, we found that mitotic aberrations, such as the delay of mitosis, multipolar centrosomes, and chromosome mis-segregation, were increased in the late-passaged hESCs (LP-hESCs) in parallel with polyploidy compared to early-passaged hESCs (EP-hESCs). Through high-resolution genome-wide approaches and by following transcriptome analysis, we found that LP-hESCs with a minimal amplicon in chromosome 20q11.21 highly expressed TPX2 (targeting protein for Xklp2), a key protein for governing spindle assembly and cancer malignancy. Consistent with these findings, the inducible expression of TPX2 in EP-hESCs reproduced aberrant mitotic events, such as the delay of mitotic progression, spindle stability, misaligned chromosomes, and polyploidy. This data suggests that the amplification and increased transcription of the TPX2 gene at 20q11.21 could contribute to an increase in aberrant mitosis due to altered spindle dynamics.

cell biology↗

Structural and molecular determinants of CCS-mediated copper activation of MEK1/2

SummaryNormal physiology relies on the precise coordination of intracellular signal transduction pathways that respond to nutrient availability to balance cell growth and cell death. We recently established a critical mechanistic function for the redox-active micronutrient copper (Cu) in the canonical mitogen activated protein kinase (MAPK) pathway at the level of MEK1 and MEK2. Here we report the X-ray crystal structure of Cu-MEK1 and reveal active site chemical ligands and oxidation state specificity for MEK1 Cu coordination. Mechanistically, the Cu chaperone CCS selectively bound to and facilitated Cu transfer to MEK1. Mutations in MEK1 that disrupt Cu(I) affinity or a CCS small molecule inhibitor reduced Cu-stimulated MEK1 kinase activity. These atomic and molecular level data provide the first mechanistic insights of Cu kinase signaling and could be exploited for the development of novel MEK1/2 inhibitors that either target the Cu structural interface or blunt dedicated Cu delivery mechanisms via CCS.Competing Interest StatementD.C.B holds ownership in Merlon Inc. D.C.B. is an inventor on the patent application 20150017261 entitled Methods of treating and preventing cancer by disrupting the binding of copper in the MAP kinase pathway. No potential conflicts of interest were disclosed by the other authors.View Full Text

biochemistry↗

Systematic identification of a nuclear receptor-enriched predictive signature for erastin-induced ferroptosis

Erastin, which has been initially identified as a synthetic lethal compound against cancer expressing an RAS oncogene, inhibits cystine/glutamate antiporters and causes ferroptic cell death in various cell types, including therapy-resistant mesenchymal cancer cells. However, despite recent emerging evidence for the mechanisms underlying ferroptosis, molecular biomarkers associated with erastin-dependent ferroptosis have not yet been identified. In the present study, we employed isogenic lung cancer cell models with therapy-resistant mesenchymal properties to show that a redox imbalance leads to glutathione depletion and ferroptotic cell death. Subsequent gene expression analysis of pan-cancer cell lines revealed that the activity of transcription factors, including nuclear factor erythroid 2-related factor 2 (NRF2) and aryl hydrocarbon receptor (AhR), serve as important markers of erastin resistance. Based on the integrated expression of genes in the nuclear receptor meta-pathway (NRM), we constructed an NRM model and validated its robustness using an independent pharmacogenomics dataset. The NRM model was further evaluated by employing it in the sensitivity testing of nine cancer cell lines for which erastin sensitivities had not yet been undetermined. Our pharmacogenomics approach has the potential to pave the way for the efficient classification of patients for therapeutic intervention using erastin or erastin analogs.

systems biology↗